Engine Mechanical (VQ40DE): Adjustments Nissan Pathfinder III рестайлинг

Adjustment

There is no manual drive belt tension adjustment. The drive belt tension is automatically adjusted by the drive belt auto-tensioner.

Scheme 6

1. Remove air duct and resonator assembly. Refer to " «REMOVAL AND INSTALLATION»(ref-519775-S20499474362012122900000) ".
2. Rotate the drive belt auto-tensioner in the direction of arrow (loosening direction of tensioner) as shown, using suitable tool. WARNING: Avoid placing hand in a location where pinching may occur if the tool accidentally comes off.
3. Remove the drive belt.

1. Perform adjustment depending on selected head thickness of valve lifter.

Scheme 7

Scheme 8

1. Measure the valve clearance.
2. Remove camshaft. Refer to " «REMOVAL AND INSTALLATION»(ref-519775-S00008818222012122900000) ".
3. Remove valve lifters at the locations that are out of the standard.
4. Measure the center thickness of removed valve lifters with micrometer.
5. Use the equation below to calculate valve lifter thickness for replacement. Valve lifter thickness calculation: t = t1+ (C1-C2) t = Valve lifter thickness to be replaced t1 = Removed valve lifter thickness C1 = Measured valve clearance C2 = Standard valve clearance: Intake: 0.26 - 0.34 mm (0.010 - 0.013 in)* Exhaust: 0.29 - 0.37 mm (0.011 - 0.015 in)* *: Approximately 20°C (68°F) Thickness of new valve lifter can be identified by stamp marks on the reverse side (inside the cylinder). INTAKE VALVE THICKNESS SPECIFICATIONS Stamp mark Thickness 788U 7.88 mm (0.3102 in) 790U 7.90 mm (0.3110 in) . . . . 840U 8.40 mm (0.3307 in) Available thickness of valve lifter: 27 sizes with range 7.88 to 8.40 mm (0.3102 to 0.3307 in) in steps of 0.02 mm (0.0008 in) (when manufactured at factory). Refer to " «STANDARD AND LIMIT»(ref-519775-S12191936182012122900000) ". EXHAUST VALVE THICKNESS SPECIFICATIONS Stamp mark Thickness N788 7.88 mm (0.3102 in) N790 7.90 mm (0.3110 in) . . . . N836 8.36 mm (0.3291 in) Available thickness of valve lifter: 25 sizes with range 7.88 to 8.36 mm (0.3102 to 0.3291 in) in steps of 0.02 mm (0.0008 in) (when manufactured at factory). Refer to " «STANDARD AND LIMIT»(ref-519775-S12191936182012122900000) ". CAUTION: Install identification letter at the end and top, "U" and "N", at each of proper positions. (Be careful of mis-installation between intake and exhaust.)
6. Install selected valve lifter.
7. Install camshaft. Refer to " «REMOVAL AND INSTALLATION»(ref-519775-S00008818222012122900000) ".
8. Manually turn crankshaft pulley a few turns.
9. Make sure that the valve clearances for cold engine are within the specifications by referring to the specified values.
10. Installation of the remaining components is in the reverse order of removal.
11. Start the engine, and check for unusual noise and vibration.

Scheme 9

Scheme 10

Scheme 11

1. Warm up engine thoroughly.
2. Release fuel pressure. Refer to " «FUEL PRESSURE CHECK»(ref-519777-S36172442522012122900000) ".
3. Disconnect fuel pump fuse to avoid fuel injection during measurement.
4. Remove intake manifold collector. Refer to " «REMOVAL AND INSTALLATION»(ref-519775-S03628430402012122900000) ".
5. Remove spark plug from each cylinder. Refer to " «REMOVAL AND INSTALLATION»(ref-519775-S40371683782012122900000) ".
6. Connect engine tachometer (not required in use of CONSULT).
7. Install compression tester with adapter onto spark plug hole. Use compression gauge whose pick up end inserted to spark plug hole is smaller than 20 mm (0.79 in) in diameter. Otherwise, it may be caught by cylinder head during removal.
8. Turn ignition switch to "START" for cranking. When the gauge pointer stabilizes, read the compression pressure and engine rpm. Perform these steps to check each cylinder. COMPRESSION PRESSURE SPECIFICATIONS Unit: kPa (kg/cm 2 , psi)/rpm Standard Minimum Differential limit between cylinders 1, 275 (13.0, 185) / 300 981 (10.0, 142) / 300 98 (1.0, 14) / 300 CAUTION: Always use a fully charged battery to obtain specified engine speed. If the engine speed is out of the specified range check the battery and recharge as necessary. Check the engine speed again with the battery properly charged. If some cylinders have low compression pressure, pour a small amount of engine oil into the spark plug hole of the cylinder to re-check it for compression. If the added engine oil improves the compression, piston rings may be worn out or damaged. Check the piston rings and replace if necessary If the compression pressure remains at a low level despite the addition of engine oil, the valves may be malfunctioning. Check the valves for damage. Replace the valve or valve seat accordingly. If two adjacent cylinders have low compression pressure and their compression remains low even after the addition of engine oil, cylinder head gaskets may be leaking. If the compression pressure is below the minimum value, check the valve clearances and parts associated with the combustion chamber (valve, valve seat, piston, piston ring, cylinder bore, cylinder head, cylinder head gasket). After repairing as necessary, measure the compression pressure again.
9. Install the components in the reverse order of removal.
10. Start the engine, and confirm that it runs smoothly.
11. Perform trouble diagnosis. If DTC appears, erase it. Refer to " «DESCRIPTION»(ref-519777-S22584415782012122900000) ".